This invention concerns transporter apparatus for use on floating type drilling vessels and, particularly, transporter apparatus capable of moving heavy equipment up and down and fore and aft on the drilling vessel. More particularly, the invention concerns transporter apparatus for handling heavy blowout preventer (BOP) stacks on floating drilling vessels which is capable of moving a BOP stack into position over the well bay on the drilling vessel preparatory to lowering the BOP stack to the well located on the sea floor and of moving the BOP stack to and placing it on a test stump for repair maintenance and testing, and to provide a storage frame for the BOP stack during movements of the vessel from one location to another.
Heretofore, heavy equipment such as blowout preventer stacks were generally moved fore and aft on floating drilling vessels by bridge-type overhead cranes which suspended the blowout preventer stack from rails. Those overhead cranes had undesirable features which the present invention overcomes. For example, bridge cranes usually could not lift the entire stack necessitating partial dismantling of the stack; and wire lines used to support the stack permitted adverse motion due to pitch and roll of the vessel. The transporter system of this invention holds the stack rigidly with reference to the vessel.